These eruptions of Muslim hysteria over perceived western mockery of Islam occur about every 20 years and always take us by surprise. Who'd have imagined that the publication in a Danish newspaper of boring and tasteless caricatures of the prophet Muhammad could mobilise the Muslim masses and set the world ablaze? Few people have actually seen these cartoons, just as almost nobody had read The Satanic Verses when the Ayatollah Khomeini's fatwa of 1989 got millions around the world baying for Salman Rushdie's blood.

More surprising still was the burning down in 1970 of the British Council Library in Rawalpindi by a furious mob in response to a column in the Times by Auberon Waugh. I can't now remember what the piece was about, but it referred to baggy trousers worn by some Muslim men as "Allah Catchers", which is what caused the trouble. In London, about 250 Muslims marched to the offices of News International where they burned a copy of the Sunday Times and demanded a boycott of the Times by Muslim governments, the expulsion of Times correspondents from Muslim countries, and the prominent publication of an apology for Waugh's "insulting and defamatory" article on Islam. The only thing that happened was Waugh's sacking by the Times, one thing the demonstrators hadn't demanded. Although his offence against Islam was of a lesser order than that of the Danish cartoons, and the tension between Islam and the west far greater today, it is hard to imagine such a craven reaction now.

Despite all the dreadful things that have happened in recent years - 9/11, 7/7, Afghanistan, Iraq - we seem to be less ready to buckle under in the face of Islamic threats than we were before. Newspapers across Europe (though not in Britain) have ignored the risks and boldly reprinted the Danish cartoons to demonstrate their support for freedom of speech.

What's odd about the present crisis is that it feels as if it's happening in a topsy-turvy wonderland in which nothing is quite as it seems. Take the recent London protest in which Muslim extremists called for the "beheading" of those who insult Islam. This, it was said, was incitement to murder, a crime calling out for criminal prosecution. But I couldn't really take it seriously, for beheading is one of the least practical forms of murder. The demonstrators might as well have been asking for the restoration of capital punishment for blasphemy.

Then there was the most notorious of the demonstrators, one who dressed as a suicide bomber and then apologised for it. How is he to be taken seriously? Not only had he served time for drug-dealing; he is called Omar Khayam, the name of the 11th-century Persian poet and astronomer celebrated for his broad-mindedness and freedom from religious dogmatism.

So I don't think we should worry too much. These periodic crises are characterised by a great deal of humbug on all sides. And last Sunday's Muslim rally in Trafalgar Square was a model of calm and moderation.